The are, unit of area
The are is exactly 100 square meters, a square ten meters on each side. It is the unit the hectare is built from, and the only one of the two that most people never meet.
It was created by decree. The French law of 18 germinal year III, 7 April 1795, which gave the metric system its names, made the are the unit of land area at one hundred square meters. The hectare is simply a hundred ares, and its name says nothing else. The are itself lost ground almost everywhere, except in Swiss and German land registers where plot sizes are still published in ares, and in the French word centiare, which is one square meter.
The are in other units
| 1 a | 0.0001 km² |
| 1 a | 0.01 ha |
| 1 a | 100 m² |
| 1 a | 1,000,000 cm² |
| 1 a | 0.0000386102 mi² |
| 1 a | 0.0247105 ac |
| 1 a | 1,076 ft² |
| 1 a | 155,000 in² |
| 1 a | 119.599 yd² |
| 1 a | 100,000,000 mm² |
| 1 a | 0.1 dunum |
| 1 a | 30.25 tsubo |
| 1 a | 0.0238095 feddan |
| 1 a | 0.0625 rai |
| 1 a | 30.25 pyeong |
| 1 a | 0.571429 qirat |
| 1 a | 0.988422 guntha |
| 1 a | 2.47105 cent |
| 1 a | 0.197684 kanal |
Frequently asked questions
How many ares are in a hectare?
A hundred exactly, which is what the prefix hecto means. A plot of 25 ares is therefore a quarter hectare, or 2 500 square meters.
What does an are look like on the ground?
A square ten meters on a side, or about two parking spaces side by side plus their aisle. It is the smallest area unit that still describes land rather than a room.
Is the are still an official unit?
It is not part of the International System, and the SI brochure keeps only the hectare among the non-SI units accepted for land area. The are survives by usage rather than by law, in cadastres and in the word centiare.